I would grab a camera and slowly start taking the entire machine apart. Using the camera take pics of all of the wires, pipes and their locations. Once it's all in pieces drop all of the metal parts in 50/50 CLR for a day or two until all scale is gone. Hand wash before re building. I would buy a new pump and solenoid from Espressoparts.com as well as their washer kit's. This will make your Silvia new again.

They have any parts you need. Believe me when I tell you it's not a hard job. Just use pic's as a map.

Not too difficult to remove from the machine for disassembly and cleaning. There is a rubber washer that is held by a strong spring against a mating brass surface. Scale on the mating surfaces can prevent the valve from sealing. The rubber will eventually deteriorate as well.

The net effect is that the OPV does not seal well at low pressures, allowing too much water to be shunted back to the reservoir, leaving none for brewing coffee. I think this is at least part of what's going on with your machine.

The thing about descaling when it desperately needed is that when not all of the rock (that's essentially what scale is) is removed, the remainder acts as a sponge for the chemical. That makes it really difficult to get rid of the chemical odor.

You may need to do some more sessions, and one piece of advice for a stronger descale, other than to use Durgol or a stronger mixture of Dezcal, is to first steam out some of the water from the boiler, so that the chemical solution isn't as significantly diluted when it enters the boiler. Heat it to steam, let the steam run while power is on for about 50 seconds, and then turn off the Silvia and let the steam bleed out. Now the chemical that you pump into the boiler will be more efficient at reacting with the scale.

calblacksmith, your link, photos and teardown have been really helpful. I don't expect to find anything near what you did in your project machine. But I will post photos.

it has been days that you have been talking about it here.

OP Jan 6? Today is Jan 7 - "days"?

I said: "I will attempt to remove and clean the OPV tomorrow. I'll report back after that." And I haven't said anything since. : )

I ordered crush washers and a boiler gasket and other consumable parts today. I will probably disassemble and descale the OPV and Boiler tonight, so they are clean and ready for assembly when the parts arrive.

If you're wondering what two doses of dezcal and a tank of 3:1 H20:CLR might do to the inside of a boiler with 11 years of scale on it, when I removed the boiler upper, this is what fell out.

The interior of the boiler was actually not that bad (since most of the scale had already been cracked off). Sorry that picture isn't in better focus. I removed the thermostats and soaked the upper boiler in distiller white vinegar (just up to the top of the interior, but not covering the top of the exterior) overnight and it's almost completely clean. Just a little touchup cleanup later tonight. I also soaked the bottom in vinegar with similar results (I ladled several tablespoons of vinegar into the boiler bottom and groove).

I wasn't able to get the OPV open, so I soaked it in WD40 overnight (I ordered a replacement gasket tip, so I wasn't concerned about WD40 permeating that gasket). This morning I was able to get it open and it contains a lot of scale too, although it's more like a paste now from the soaking. I'll clean these with vinegar tonight. I may heat the vinegar for a more vigorous, shorter reaction, and described here: http://milksnot.com/content/silvia-pressure-mod

Once they're all cleaned I'll reassemble what I can while I wait for the Boiler gasket and other parts from espressoparts.com.

If after all of this it turns out to be the pump after all, at least the new pump will be working with a clean, rebuilt boiler circuit!

Order a new OPV. The petrolium residue from the WD40 will not be able to be washed off (it soaks into the surface of the metal and is there permenantly), it will taint the water and it is not healthful to drink, sorry about that, you should have asked before soaking, we would have told you so first. YMMV!

As to the other photos, yep, it was time to disassemble and do a full cleaning, chemical treatment only got the process started, it would have been a long, long time flushing over and over and over with chemicals alone. Good for you, by taking on the project, you now know what you have and are starting with a like new inside machine.

In real life, my name isWayne P.Anything I post is personal opinion and is only worth as much as anyone else's personal opinion. YMMV!

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